I purchased two 0.1nm Ha filters from Omega filters (ebay store) thinking I'd try to put together a DIY Ha scope along the lines of Groski and others. They've laid idle for several months and I think I have to admit I'm not going to get around to this project anytime soon.

Each filter is the thin "blue" version. One has a peak just inside 656.3nm and the other a peak at around 657.0. They would require a tilt system, ERF, and a filter to exclude blue light to function properly.

Together they cost me $220, asking $150.

I'll add photos later - I have them but my computer isn't reading the camera's disk.